ICSharpCode.NRefactory.MonoCSharp.Nullable.LiftedBinaryOperator.EmitEquality C# (CSharp) Method

		void EmitEquality (EmitContext ec)
		{
			//
			// Either left or right is null
			// 
			if (UnwrapLeft != null && Binary.Right.IsNull) { // TODO: Optimize for EmitBranchable
				//
				// left.HasValue == false 
				//
				UnwrapLeft.EmitCheck (ec);
				if (Binary.Oper == Binary.Operator.Equality) {
					ec.EmitInt (0);
					ec.Emit (OpCodes.Ceq);
				}
				return;
			}

			if (UnwrapRight != null && Binary.Left.IsNull) {
				//
				// right.HasValue == false 
				//
				UnwrapRight.EmitCheck (ec);
				if (Binary.Oper == Binary.Operator.Equality) {
					ec.EmitInt (0);
					ec.Emit (OpCodes.Ceq);
				}
				return;
			}

			Label dissimilar_label = ec.DefineLabel ();
			Label end_label = ec.DefineLabel ();

			if (UserOperator != null) {
				var left = Left;

				if (UnwrapLeft != null) {
					UnwrapLeft.EmitCheck (ec);
				} else {
					// Keep evaluation order same
					if (!(Left is VariableReference)) {
						Left.Emit (ec);
						var lt = new LocalTemporary (Left.Type);
						lt.Store (ec);
						left = lt;
					}
				}

				if (UnwrapRight != null) {
					UnwrapRight.EmitCheck (ec);

					if (UnwrapLeft != null) {
						ec.Emit (OpCodes.Bne_Un, dissimilar_label);

						Label compare_label = ec.DefineLabel ();
						UnwrapLeft.EmitCheck (ec);
						ec.Emit (OpCodes.Brtrue, compare_label);

						if (Binary.Oper == Binary.Operator.Equality)
							ec.EmitInt (1);
						else
							ec.EmitInt (0);

						ec.Emit (OpCodes.Br, end_label);

						ec.MarkLabel (compare_label);
					} else {
						ec.Emit (OpCodes.Brfalse, dissimilar_label);
					}
				} else {
					ec.Emit (OpCodes.Brfalse, dissimilar_label);
				}

				var args = new Arguments (2);
				args.Add (new Argument (left));
				args.Add (new Argument (Right));

				var call = new CallEmitter ();
				call.EmitPredefined (ec, UserOperator, args);
			} else {
				if (ec.HasSet (BuilderContext.Options.AsyncBody) && Binary.Right.ContainsEmitWithAwait ()) {
					Left = Left.EmitToField (ec);
					Right = Right.EmitToField (ec);
				}

				//
				// Emit underlying value comparison first.
				//
				// For this code: int? a = 1; bool b = a == 1;
				//
				// We emit something similar to this. Expressions with side effects have local
				// variable created by Unwrap expression
				//
				//	left.GetValueOrDefault ()
				//	right
				//	bne.un.s   dissimilar_label
				//  left.HasValue
				//	br.s       end_label
				// dissimilar_label:
				//	ldc.i4.0
				// end_label:
				//

				Left.Emit (ec);
				Right.Emit (ec);

				ec.Emit (OpCodes.Bne_Un_S, dissimilar_label);

				//
				// Check both left and right expressions for Unwrap call in which
				// case we need to run get_HasValue() check because the type is
				// nullable and could have null value
				//
				if (UnwrapLeft != null)
					UnwrapLeft.EmitCheck (ec);

				if (UnwrapRight != null)
					UnwrapRight.EmitCheck (ec);

				if (UnwrapLeft != null && UnwrapRight != null) {
					if (Binary.Oper == Binary.Operator.Inequality)
						ec.Emit (OpCodes.Xor);
					else
						ec.Emit (OpCodes.Ceq);
				} else {
					if (Binary.Oper == Binary.Operator.Inequality) {
						ec.EmitInt (0);
						ec.Emit (OpCodes.Ceq);
					}
				}
			}

			ec.Emit (OpCodes.Br_S, end_label);

			ec.MarkLabel (dissimilar_label);
			if (Binary.Oper == Binary.Operator.Inequality)
				ec.EmitInt (1);
			else
				ec.EmitInt (0);

			ec.MarkLabel (end_label);
		}